Title: Development Economics
1Development Economics
2Risky environment
- Rural households in LDCs are confronted to a
risky environment - Climatic risk
- Natural catastrophe
- Illness
-
- Very variable income over time.
- Spatially correlated risks
- Survival risk for those individual close to the
subsistence level.
3Some sources of risk data from Ethiopia
4- If agents are risk adverse, they get a higher
utility from a certain income than from an income
flow with the same expectancy but positive
variance. - Hence, they will try to smooth their consumption
flow. - Therefore, they need to transfer resources across
time.
5Coping with shocks ex-post
- Self-insurance through
- Running down of liquid savings
- Running down of assets stocks (Livestock,
Jewellery) - Child labour, school drop out long term
consequences on human capital accumulation. - In the long run, might lead to poverty traps.
- In case of aggregate shocks, both asset prices
and wages are adversely affected. - Access to credit
- Role of family / migrations
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7Self-insurance and bullocks Rosenzweig Wolpin
(1993) ICRISAT villages
- In this setting no land sale, but active land
rental market. - Largest component of non-land wealth is bullocks
for bullocks, no rental market but regionally
integrated market for sales. - Since there is no rental, there are productivity
gains to owning bullocks. - 86 of the HH were involved in a least one
transaction in bullocks over 10 years, suggesting
the possibility of distress sales. - Indeed, because of regional integration, bullock
prices are immune to village specific production
shock against which farmers seeks insurance. - 60 of the sales where made to buyers outside the
village. - Results show that the probability of a bullock
purchase increase with income and probability of
a sale decreases. Further, farmers holding higher
stocks of bullocks are less likely to make a
purchase in the future, suggesting a target
level. - RW also suggest that it results in sub-optimal
holding of bullocks (0.94 instead of 2).
8Managing risk ex-ante
- Objective consumption smoothing
- Production choices
- Risk diversification
- Share-cropping
- Insurance.
9Risk sharing
- Possibility of mutual insurance in groups where
individuals suffer from idiosyncratic shocks. - A certain amount of consumption smoothing is
indeed observed (Paxson, Thailand, Townsend,
India), but no perfect insurance. - Issue choice of reference group for risk
sharing. (Munshi Rosenzweig, India cast
rather than village)
10Incomplete intertemporal markets
- Informational issue
- Costly, asymmetrical, environment specific.
- Trade-off between risk diversification
(geographic) and information acquisition. - Make the implementation of formal insurance
scheme difficult. - Gives an advantage to informal mechanisms, in
particular those relying on family networks - Migrations (Stark various co-authors).
- Marriages (Rosenzweig Stark ICRISAT)
11Perfect Insurance model
- At any date, each farmers income is given by
- A is average income, e is a random idiosyncratic
shock (independant from other farmers shocks),
and ? is an aggregate shock at the village level. - If farmers pay the realized value of e into a
common fund, idiosyncratic shocks can be insured
against. - The insured income is then given by
-
- still fluctuates, but carries less risk
than Y. The aggregate shock cannot be wiped away
by mutual insurance within the village. - Hence, a determinant of mutual insurance is the
relative importance of idiosyncratic risk to
aggregate risk.
12Importance of covariate vs idiosyncratic some
results
- Deaton, Cote dIvoire, finds that common
components for individual villages explain very
little of the variation in household income
changes during 1985-6. - Townsend, Thailand (1995), finds that there are
very few common regional components in income
growth. - Morduch (2001) studies the ICRISAT villages and
shows that idiosyncratic risk accounts for 75-96
percent of the total variance in income. - Reporting data for villages in Northern Nigeria,
Udry also finds similar magnitudes of covariant
risk.
13Empirical test of perfect insurance
- Controlling for movements in aggregate
consumption, individual hh income should not
affect consumption. - But Hh consumption should follow village average
consumption - Regress individual consumption on av. consumption
and individual income - cI a ?1 ca ?2 x ?I
- Where the coefficient on the individual income
shock ?2 is expected to be equal to zero. - That is, the coefficients on household level
transitory variations in income should be zero
and consumption should move one to one with the
village average (hence ?1 should be equal to 1).
14Testing for perfect insurance Townsend (1994),
ICRISAT villages again.
- Townsend looks at hh Y average Y this residual
can be interpreted as idiosyncratic risk (it
could also include a lot of measurement error).
It fluctuates independently across hh. hence
there should be room for mutual insurance. - Regression of C on Y and average C. He finds
that indeed coeff of hh income is close to zero,
and also coeff of sample average C close to one
(less robust result). - Regression of distance to the mean in consumption
on the same in income individual income
significantly affects individual consumption, but
the coefficient is small. Estimates elasticity of
only 14. Further, events such as sickness are
not significant in determining consumption. - Smoothing does take place. Impossible to tell
whether it is from mutual insurance of other
mechanisms (self-insurance or credit).
15- Townsend (1994) and Morduch (1995) both find that
landless household are less able to smooth
consumption. - Morduch underlines the hidden cost of smoothing
household may forego the cultivation of a crop
with high expected yields because it is more
risky - Results on consumption smoothing are also found
in Thailand (Paxson 1992) and Cote dIvoire
(Deaton 1994), although full insurance is
rejected.
16Limits to insurance information
- Final outcome might not be easily observable so
that a person might illegitimately claim
insurance transfers. - Easier to check if insurer is near, e.g. within
the village. - Role of social capital
- Advantage to informal schemes.
- Pb the relevant group is the one within which
the information flows.
17Moral hazard.
- In case of full insurance, how is it possible to
be sure that everyone makes the best effort to
obtain the high outcome. - Assume two outcomes H and L
- Probability to obtain H depends on effort with
effort of cost C, prob is pgt q without effort. - Without insurance, net expected utility with
effort is pu(H)(1-p)u(L)-C (1) - and without effort qu(H)(1-q)u(L)
(2) - Assume (1)gt(2).
- If farmers are risk adverse
- u(pH(1-p)L)gtpu(H)(1-p)u(L)
18- Insuring such level of utility is possible if
each farmer obtaining H put (1-p)(H-L) into the
pot, while each farmer with output L receives
p(H-L). Every one always gets pH(1-p)L for sure. - Pb how to make sure each one puts effort in.
- Note X consumption of farmer with H and Y the
consumption of farmer with L. - An insurance scheme is viable if
- pX(1-p)YpH(1-p)L
- If X and Y are too close, people will not make
any effort.
19- How close can they be? Effort will be put in as
long as - pu(X)(1-p)u(Y)-Cqu(X)(1-q)u(Y)
- hence the closest they can be is given by
(p-q)u(X)-u(Y) C - The second best insurance scheme is a viable
scheme that respects the above constraint. - In any solution, XgtY . Hence, the individual
consumption needs to move with individual income.
20- Here again, group with better information about
each other are in a better position to provide
mutual insurance. - Altruism also facilitates (because it allows
internalisation of cost to deviation). Hence the
role of the extended family or kin group. - Drawback few possibilities of diversification
within the extended family, except thanks to
marriage and migration.
21Enforcement
- High output individuals have incentives to
deviate. Their gain would be - Gu(H)-u(M)
- where M is the level of consumption under
the insurance scheme. - The loss from deviation is given by
- LNu(M)-pu(H)(1-p)u(L) S
- Where S is measure of utility cost of social
sanctions and N the number of periods for which
the insurance arrangement is assumed to hold.
22- The enforcement constraint requires that LgtG, so
that - Nu(M)-pu(H)(1-p)u(L)Su(H)-u(M)
- Role of S
- Role of N perceived instability of an insurance
scheme is self-fulfilling N is driven down, so
the enforcement constraint fails and the scheme
falls apart. - The net effect of the difference between H and L
can go either way it both gives incentives to
deviate but increases the benefits from insurance
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24Enforcement and imperfect insurance.
- If the enforcement constraint fails, then perfect
insurance is unattainable. - The enforcement constraint can be rewritten as
- U(X)Npu(X)(1-p)u(Y)
u(H)Npu(H)(1-p)u(L)-S - The RHS term is constant, depends on parameters,
notably S. - The LHS term fisrt increases with X and then
decreases. - If RHS low enough, perfect insurance is
sustainable. - If RHS increases (e.g. because social norms
weaken), the second best insurance scheme implies
again a higher X and then a lower Y than under
perfect insurance. Hence, individual consumption
has to move with individual income. - A further increase in RHS will lead to a point
where no insurance is available.
25- The blurring between credit and insurance (Udry
Nigeria) allows to introduce some history
dependence in the determination of payments a
contributor at time t will be entitled to a
bigger share of the returns at time t1.
26Informal insurance
- Social capital help going around these issues.
- Information, enforcement, repeated relationships,
social norms, interlinked contracts. - Examples
- Transfers in Botswana responsive to drought
(Lucas Stark), to unemployment (livestock
herding, Cashdan) - Transfers in India sensitive to shortfalls in
income (Rosenzweig) - Transfers from migrant daughter in case of
illness in the Dominican Republic (De la Brière
alii) - Help through loans in India (fisheries, Platteau)
27Welfare impacts of incomplete insurance
- Rose, India, negative rainfall shocks ? higher
boy girl mortality in landless households, not
households with land - Jacoby Skoufias, Peru, take kids out of school
- Foster, child growth affected during after
floods in Bangladesh in 1988
28Welfare impacts of incomplete insurance
- Behrman, India, child health, particularly girls
negatively affected before major harvest - Dercon Krishnan, Ethiopia. Intra-hh dimension,
health shocks result in particularly large losses
for women 1.6-2.3 percent of body weight